Classes¶

struct param_type

Public Types¶

typedef _IntType result_type

Public Member Functions¶

poisson_distribution (const param_type &__p)
poisson_distribution (double __mean)
template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void __generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng)
template<typename _ForwardIterator , typename _UniformRandomNumberGenerator > void __generate (_ForwardIterator __f, _ForwardIterator __t, _UniformRandomNumberGenerator &__urng, const param_type &__p)
template<typename _UniformRandomNumberGenerator > void __generate (result_type *__f, result_type *__t, _UniformRandomNumberGenerator &__urng, const param_type &__p)
result_type max () const
Returns the least upper bound value of the distribution. double mean () const
Returns the distribution parameter mean. result_type min () const
Returns the greatest lower bound value of the distribution. template<typename _UniformRandomNumberGenerator > result_type operator() (_UniformRandomNumberGenerator &__urng)
Generating functions. template<typename _UniformRandomNumberGenerator > result_type operator() (_UniformRandomNumberGenerator &__urng, const param_type &__p)
param_type param () const
Returns the parameter set of the distribution. void param (const param_type &__param)
Sets the parameter set of the distribution. void reset ()
Resets the distribution state.

Friends¶

template<typename _IntType1 , typename _CharT , typename _Traits > std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > &__os, const std::poisson_distribution< _IntType1 > &__x)
Inserts a poisson_distribution random number distribution __x into the output stream __os. bool operator== (const poisson_distribution &__d1, const poisson_distribution &__d2)
Return true if two Poisson distributions have the same parameters and the sequences that would be generated are equal. template<typename _IntType1 , typename _CharT , typename _Traits > std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > &__is, std::poisson_distribution< _IntType1 > &__x)
Extracts a poisson_distribution random number distribution __x from the input stream __is.

template<typename _IntType = int>¶

class std::poisson_distribution< _IntType >"A discrete Poisson random number distribution.

The formula for the Poisson probability density function is $p(i|) = ac{^i}{i!} e^{-}$ where $$ is the parameter of the distribution.

Since

template<typename _IntType = int> typedef _IntType std::poisson_distribution< _IntType >::result_type¶

The type of the range of the distribution.

template<typename _IntType = int> result_type std::poisson_distribution< _IntType >::max () const [inline]¶

Returns the least upper bound value of the distribution.

References std::numeric_limits< _Tp >::max().

template<typename _IntType = int> double std::poisson_distribution< _IntType >::mean () const [inline]¶

Returns the distribution parameter mean.

template<typename _IntType = int> result_type std::poisson_distribution< _IntType >::min () const [inline]¶

Returns the greatest lower bound value of the distribution.

template<typename _IntType = int> template<typename _UniformRandomNumberGenerator > result_type std::poisson_distribution< _IntType >::operator() (_UniformRandomNumberGenerator & __urng) [inline]¶

Generating functions.

References std::poisson_distribution< _IntType >::operator()().

Referenced by std::poisson_distribution< _IntType >::operator()().

template<typename _IntType > template<typename _UniformRandomNumberGenerator > poisson_distribution< _IntType >::result_type std::poisson_distribution< _IntType >::operator() (_UniformRandomNumberGenerator & __urng, const param_type & __param)¶

A rejection algorithm when mean >= 12 and a simple method based upon the multiplication of uniform random variates otherwise. NB: The former is available only if _GLIBCXX_USE_C99_MATH_TR1 is defined.

Reference: Devroye, L. Non-Uniform Random Variates Generation. Springer-Verlag, New York, 1986, Ch. X, Sects. 3.3 & 3.4 (+ Errata!).

References std::abs(), std::numeric_limits< _Tp >::epsilon(), std::log(), and std::numeric_limits< _Tp >::max().

template<typename _IntType = int> param_type std::poisson_distribution< _IntType >::param () const [inline]¶

Returns the parameter set of the distribution.

template<typename _IntType = int> void std::poisson_distribution< _IntType >::param (const param_type & __param) [inline]¶

Sets the parameter set of the distribution.

Parameters

template<typename _IntType = int> void std::poisson_distribution< _IntType >::reset () [inline]¶

Resets the distribution state.

References std::normal_distribution< _RealType >::reset().

template<typename _IntType = int> template<typename _IntType1 , typename _CharT , typename _Traits > std::basic_ostream< _CharT, _Traits > & operator<< (std::basic_ostream< _CharT, _Traits > & __os, const std::poisson_distribution< _IntType1 > & __x) [friend]¶

Inserts a poisson_distribution random number distribution __x into the output stream __os.

Parameters

Returns

template<typename _IntType = int> bool operator== (const poisson_distribution< _IntType > & __d1, const poisson_distribution< _IntType > & __d2) [friend]¶

Return true if two Poisson distributions have the same parameters and the sequences that would be generated are equal.

template<typename _IntType = int> template<typename _IntType1 , typename _CharT , typename _Traits > std::basic_istream< _CharT, _Traits > & operator>> (std::basic_istream< _CharT, _Traits > & __is, std::poisson_distribution< _IntType1 > & __x) [friend]¶

Extracts a poisson_distribution random number distribution __x from the input stream __is.

Parameters

Returns